My preference is to change the oil by pulling the drain plug after the engine oil has had a chance to get hot. In a diesel, the high-detergent Shell Rotella oil has presumably taken up a lot of carbon particles (aka "soot") in suspension during the warm-up. So, I pull up to a stop at the front of the garage, throw the pan under the car and unscrew the plug.

Whoooosh! Out comes two gallons of pitch black oil in about 30 seconds. No chance for any soot to settle out. And a good chance for any heavier gunk in the bottom of the oil pan to get flushed out as well.

As far as the hot drain plug and oil (ooch ooch eech ouch ouch) I just take the pain......

How long does it take one of these suction devices to empty two gallons of oil?